Three-Stage Drawer Guide With Adjusting Bearings for Clearance Alignment

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Solution Overview

Problem

Three-stage telescopic guides for pharmacy furniture experience vertical and transversal clearance issues between stages, leading to reduced accuracy, misalignment, and increased torsion forces, which compromise the reliability and smooth operation of drawers with automatic re-entry functionality.

Innovation Solution

Incorporating a transversal adjusting bearing with a vertical rotation axis and guide bearings at different heights on the second stage, along with a C-shaped first stage with a flange for guiding, to align and recover clearance, ensuring precise alignment and reduced torsional stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the height of the C-section of the first stage is made greater than the diameter of the second-stage bearings for easy coupling and assembly, then the ease of manufacture is improved, but the clearance between the guide and the bearings increases, leading to reduced accuracy of movement, less sliding characteristic, guide locking, misaligned stages, and increased load on the bearings

Engineering Contradiction:
Improveease of coupling and assemblyVSAvoidaccuracy of movement
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

An adjusting bearing is introduced as an intermediary element between the first stage C-shaped guide and the second stage. This adjusting bearing compensates for the clearance created by the height difference, maintaining both easy assembly and high precision movement without requiring expensive tight-tolerance bearings

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the vertical position parameter of the bearing axis relative to the C-section height. By positioning the bearing axis at a specific height within the C-section and using the adjusting bearing to compensate for clearance, the system achieves both easy assembly (larger height difference) and high precision (clearance compensation)

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the clearance between the guide and the bearings is reduced by using more accurate assembly, then the accuracy of movement is improved, but the costs increase and installation becomes difficult

Engineering Contradiction:
Improveaccuracy of movementVSAvoidinstallation difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The adjusting bearing serves as a mediator that eliminates the need for expensive high-precision bearings and difficult installation procedures. It provides the necessary clearance compensation through a simple adjustable mechanism that is easy to install and maintain

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The adjusting bearing is designed to be easily adjustable by the installer, allowing self-correction of alignment and clearance issues during installation without requiring specialized tools or expertise. The system essentially adjusts itself to the correct configuration

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If the clearance between the guide and the bearings is reduced, then the sliding characteristic is improved, but the automatic re-entry function cannot be achieved

Engineering Contradiction:
Improvesliding characteristicVSAvoidautomatic re-entry function
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The system optimizes the vertical clearance parameter to a specific range that allows both smooth sliding and automatic re-entry. The adjusting bearing enables precise control of this parameter, creating optimal conditions for the drawer to automatically return to its closed position under gravity while maintaining smooth operation throughout the travel range

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enhances alignment precision, cancels vertical clearance, and reduces torsional stress, allowing for smooth and reliable operation of pharmacy furniture drawers with improved mechanical resistance and automatic re-entry functionality.

Implementation Method 1

the second stage comprises at least a roller bearing with a horizontal axis, which contacts a first guiding surface of the first stage

Methodology Applied
Scientific EffectRoller bearing: Roller

Implementation Method 2

said second stage is provided with at least one transversal adjusting bearing, said bearing having a substantially vertical rotation axis

Methodology Applied
Scientific EffectRoller bearing: Roller

Data Source

PatentEP2149315B1Guide for overhang extractable drawers
Publication Date: 2010.09.15 ICAS
  • EP2149315B1 patent drawingFigure 1
  • EP2149315B1 patent drawingFigure 2
  • EP2149315B1 patent drawingFigure 3~4

AI summary

Three stage (100, 200, 300) telescopic guide (10, 11), in particular for extractable drawers of pharmacy furniture, wherein the second stage (200) is guided by the first stage (100) by means of roller bearings, which comprise at least an alignment and clearance recovery bearing (231, 232); preferably there are provided guide bearings (230) having a horizontal axis, a rear bearing (231) for vertical clearance recovery and further bearings (232) for alignment and transversal adjustment.